function updateList() {
	db.transaction(function(tx) {
		tx.executeSql("SELECT * FROM RssList", [], readSuccess, errorCB);
	}, errorCB);
}

function readSuccess(tx, result) {
	var updatenum = 0;
	var rowsLen = result.rows.length
	$.each(result.rows, function(index) {
		var row = result.rows.item(index);
		$.getFeed({
			url : row['Link'],
			dataType : "xml",
			success : function(feed) {
				updatenum += feed.items.length;
				rowsLen-=1;
				if (rowsLen==0) {
					alert("本次一共更新了"+updatenum+"条新闻");
				}
			}
		});
	});
}